Window droppings

You know - either there's a window leaving overlapping copies of itself behind
as you drag it around, or there's a window that's not really there any more but
sort of blocks anything else from updating that area of the screen properly. I've
seen this in a million versions of Windows, but I think not recently. Why does it
happen?

Answer:
This has to do with the kind of "window
manager" an operating system uses.

A "compositing" window manager, like the evocatively-named "Desktop
Window Manager" that's been used by Windows since Vista, sits between the screen
and all programs that want to display stuff on it. The manager listens to what the programs
want, and to what the user is trying to do (like moving windows around, for instance).
It then creates and updates the screen image based on all of that input, without being
forced to do anything by anybody. The display a compositing manager creates can include
fancy stuff like flip-book program switching; none of the programs need to know how
to turn their window into a 3D perspective flipbook, the manager does it for them.

As long as a compositing window manager is itself healthy, no weird stuff like blank
or trail-leaving windows from broken programs should make it to the monitor. It doesn't
stop programs from crashing, but when a program does crash the window manager should
be able to elegantly redraw that program's non-functional window in new places (and
shapes, and sizes), without leaving garbage behind.

A "non-compositing" window manager, on the other hand, is the simpler kind that lets
programs take care of drawing and re-drawing their windows themselves. They generally
do this via functions built into the operating system - every program doesn't contain
specific code for what its maximise/minimise boxes and scroll bars and so on should
look like - but if you drag Program A's small window across Program B's large window,
either or both of those programs and the OS functions that dumbly do their bidding have
to be conscious and responding to hails. If one or more component in the screen-drawing
committee isn't working, the little window won't be drawn properly, and/or the parts
of the bigger window or desktop it obscured won't be re-drawn properly.

Because the whole desktop interface doesn't have any real underlying similarities
with the physical-documents-on-a-physical-desktop that it's designed to resemble, broken
programs and/or delinquent window managers can allow windows to leave trails, or other
windows to go blank and become unmovable, or all or part of a window that's meant to
be "behind" another to be visible "in front" instead. Compositing window managers, used
by all of Microsoft and
Apple's OSes for
some time now, keep this weirdness at bay.

Religious conversion

I recently switched from Firefox to Chrome in Windows 7 x64 Very Professional
Etc, and almost everything is fine. The only thing that is not fine is that I can't
make Chrome the default browser. Whenever some piece of software tries to open something
in a browser, I always get Firefox again. (Well, except for some awful business
software I've got that seems to have Internet Explorer hardcoded in it, but I don't
expect you to fix that. Jesus couldn't fix that.)

Everybody else seems to be able to set a damn default browser. Why can't I?

Gabriel

Answer:
Congratulations! You are not using your computer stupidly!

(Actually, there are a few other ways this could happen, but a little correspondence
nailed down this cause.)

Changing the default browser is not something a standard
limited Windows
user account is able to do. It's a relatively minor system setting, but it's still a
system setting, with significant possibilities for malicious action if it's subverted.
If the currently-logged-in user account can change the default browser, then malware
inadvertently run by the logged-in user can change it too, and quietly swapping in a
whole monkeyed-with browser allows malware-creators some gorgeous criminal opportunities.

When you install Chrome while logged in as a restricted user rather than as an administrator,
you get it installed to your own user profile, and can't set it as default.

To change this, then presuming you know the administrator login for your computer,
just uninstall Chrome, then right-click the Chrome installer (the little ChromeSetup.exe
program that downloads the rest of Chrome when you run it...) and select Run As Administrator,
and give it the admin username and password.

Now you'll get the "normal", default-browser installation - for all user accounts
- that those of us who foolishly run as admin all the time have.

Vivaldi = Van Halen

Some of my MP3s are quiet, and some of them are loud. I like random play for
background music at home, but if I turn Albinoni up until I can hear it and Judas
Priest is next in the playlist, it's... an alarming contrast.

Is there a way to iron out everything's relative loudness?

B.

The audiophile-practical-joke possibilities of MP3Gain
have only just occurred to me.

Answer:
There are a few ways.

The generic audio-engineering term for something that smooths out volume changes
is a "compressor".
They're routinely used to keep the volume of radio stations steady, and to squeeze all
perceptible dynamic range out of a distressing amount of modern music.

You can get compressor plug-ins for various music players. You could also batch-process
all of your MP3s through a compressor in an audio-editing program like Audacity (which
is free), but this is not a great idea
because now they'll be compressed forever. They'll also be re-compressed, in
the lossy-MP3-audio-encoding
sense, inescapably losing some data. If you're making CDs to play in your car, though,
compressing the audio before writing it to disc can be quite helpful.

And then there's "normalisation",
which changes the maximum volume of a given audio file to a given value. Most digital
popular music these days has a high maximum volume, as high as it can be set without
clipping, and often a bit
higher still. It's still very easy, however, to find audio files whose maximum volume
is far lower than this, and if you random-play low-max-volume music along with high-max-volume
music, the latter will vastly out-shout the former. Normalisation doesn't change the
ratio between the volumes of the loud and the quiet parts of a given piece of
music; it just sets the highest volume to a given value.

There are a couple of ways to normalise the volume of compressed-in-the-MP3-sense
audio files without losing any data by recompressing it. First, there's the "ReplayGain"
pseudo-standard, which adds a little data to the file header - not touching the actual
audio - which tells compatible players how much to turn the volume up, or down, for
that file. There's also MP3Gain, which
does modify the data but in a lossless, perfectly reversible way, and which has
a clever overall-loudness algorithm that figures out how much you can boost each individual
file, or all the files that make up an album or symphony, without any chance of distortion.

That last situation - albums and symphonies - is the only good reason not to MP3Gain
your whole MP3 library. If you've got a symphony, say, with a loud first movement and
a quiet second and a loud third, and they're all in one audio file, then normalising
it won't make the volume ratios any different. The different movements of a symphony
are often encoded into separate audio files, though, and blindly normalising all of
them will then make the quiet movement much closer in volume to the loud ones. Some
people don't mind this at all, and it remains a good idea for listening in places with
lots of background noise - while jogging, or in the car, say. But if you want to normalise
audio without losing the intended volume contrast between separately-encoded parts of
one overall piece of music, you have to use something like MP3Gain that can normalise
them all together.

I have a shiny new GeForce 770, replacing poxy onboard graphics. I have discovered
that the 770 needs a couple of extra power plugs to run it, which my computer's
500W PSU does not provide. I've got several spare 4-pin drive
powerplugs, though, and you can get
cheap adapters that can turn drive power plugs into all of the special video
power plugs.

I am clever enough to buy and plug in those adapters. I am also clever enough
to know that those adapters do not magically make my PSU actually able to provide
enough power to run this card the size of a skateboard. Is it acceptable to give
it a try and buy a new PSU if the old one doesn't cut it, or is this likely to blow
something up?

Finn

Answer:
Yes, it is possible to damage the PSU, the video card, or various other components by
overstressing your power supply. What will probably happen if the PSU isn't up
to the task, though, is just that the computer will hang, or the PSU will turn itself
off.

The full Thermal Design
Power for a GeForce GTX 770 is
230 watts, and
there are factory-overclocked versions that can draw more. The PC PSU market is also
hideously debased. Off-brand PSUs are commonly rated completely
fictitiously, and even brand-name units are not necessarily able to reliably deliver
their full rated current on any rail.

(Note that the Thermal Design Power is the most power a device can be expected to
draw over any length of time; it's the amount of heat from that device that the cooling
system has to be able to handle. Peak power consumption can be higher, and real-world
power consumption is often quite a bit lower. When you're just using 2D desktop applications,
all 3D-accelerated graphics cards will consume far less than their TDP.)

A new, real 500W PSU will probably be OK with your new video card, provided
you don't have a fire-breathing overclocked CPU to run at the same time. Most cheap
PSUs with a "500W" sticker on them will not be good enough, though. Any proper brand-name
PSU from 500 watts on up should come with the PCIe power plugs natively hanging off
it.

PSUs with enormous capacity have existed since before PCIe did, though; if you've
got an old PSU with, say, a genuine 750-watt rating, then adapting its drive plugs into
PCIe power plugs may work fine. Especially if you use one of the adapter cables that
has two "Molex" sockets
leading to just one four- or six-pin video-card power plug. Those adapters cost about
the same
approximately nothing as do adapters with only one Molex socket.

CCed to Child Protective Services

So my delectable kid just kept herself silently busy for a while jamming a pen
into the vent hole in the side of my laptop, which offers direct access to the thin
copper fins of the heat sink. The part of the heat sink visible through the vent
now looks like a forest that several tanks have driven through.

When I have finished drowning my daughter in the toilet, is there any chance
that I can just straighten the fins out again and be OK?

Ellie

Answer:
Yeah, you'll probably get away with that. The fin-straightening, I mean, not the infanticide.

Laptop heat-sinks are often on the end of a
heatpipe, a
sealed tube containing a
liquid that boils at the hot end, on the chips in the middle
of the computer, and condenses at the cool end, where the heat-sink and fan are, taking
the heat with it. If the tube is ruptured, the heat transfer won't work any more and
your laptop will run hot.

(Modern auto-throttling CPUs can often survive with this sort of reduced cooling.
if you're not stressing the computer, then even if its cooling is horribly compromised,
it'll probably still be OK running at its minimum possible clock speed. It is also possible
to inexpensively purchase replacement heat-pipes and cooling fans for many laptops -
people on eBay sell parted-out laptops
all the time, and those second-hand parts are usually fine. A laptop with dead fan
bearings that sound as if they're grinding coffee can probably
be brought back to full functionality, if you've got a few basic hand tools and a downloaded
service manual. It can be quite easy to replace your laptop's cooling components,
or... not.)

Fortunately, it's not easy to damage a laptop heat pipe without dismantling or grossly
damaging the laptop itself. So your problem is probably limited to the bent fins. You
may even be able to get them acceptably straight again without taking the laptop apart,
by levering them back with a paring knife or nail file. The heat sink probably won't
be a lot longer than it's wide, though, so take care not to stab right through the heat
sink and further into the innards of the computer.